commit 7957ed41b88518c77f6f41f50654d4954a98c5db
Author: David Edmundson <kde@davidedmundson.co.uk>
Date:   Sun Feb 3 18:36:28 2019 +0000

    scale

diff --git a/plugins/platforms/hwcomposer/egl_hwcomposer_backend.cpp b/plugins/platforms/hwcomposer/egl_hwcomposer_backend.cpp
index 3c96db118..7d8d55c82 100644
--- a/plugins/platforms/hwcomposer/egl_hwcomposer_backend.cpp
+++ b/plugins/platforms/hwcomposer/egl_hwcomposer_backend.cpp
@@ -130,6 +130,10 @@ bool EglHwcomposerBackend::makeContextCurrent()
         qCWarning(KWIN_HWCOMPOSER) << "Error occurred while creating context " << error;
         return false;
     }
+
+    QSize overall = m_backend->size();
+    glViewport(0, 0, overall.width(), overall.height());
+
     return true;
 }
 
diff --git a/plugins/platforms/hwcomposer/hwcomposer_backend.cpp b/plugins/platforms/hwcomposer/hwcomposer_backend.cpp
index 30971757d..447504cb2 100644
--- a/plugins/platforms/hwcomposer/hwcomposer_backend.cpp
+++ b/plugins/platforms/hwcomposer/hwcomposer_backend.cpp
@@ -250,7 +250,7 @@ void HwcomposerBackend::init()
     setReady(true);
 }
 
-QSize HwcomposerBackend::screenSize() const
+QSize HwcomposerBackend::size() const
 {
     if (m_output) {
         return m_output->pixelSize();
@@ -258,6 +258,22 @@ QSize HwcomposerBackend::screenSize() const
     return QSize();
 }
 
+QSize HwcomposerBackend::screenSize() const
+{
+    if (m_output) {
+        return m_output->pixelSize() / m_output->scale();
+    }
+    return QSize();
+}
+
+int HwcomposerBackend::scale() const
+ {
+    if (m_output) {
+        return m_output->scale();
+    }
+    return 1;
+}
+
 void HwcomposerBackend::initLights()
 {
     hw_module_t *lightsModule = nullptr;
@@ -508,6 +524,7 @@ HwcomposerOutput::HwcomposerOutput(hwc_composer_device_1_t *device):
     initWaylandOutputDevice(QString(), QString(), QByteArray(), {mode});
     setInternal(true);
     setEnabled(true);
+    setScale(3);
     setWaylandMode(m_pixelSize, mode.refreshRate);
 }
 
diff --git a/plugins/platforms/hwcomposer/hwcomposer_backend.h b/plugins/platforms/hwcomposer/hwcomposer_backend.h
index 5c6085df1..c660070f3 100644
--- a/plugins/platforms/hwcomposer/hwcomposer_backend.h
+++ b/plugins/platforms/hwcomposer/hwcomposer_backend.h
@@ -75,11 +75,11 @@ public:
     Outputs outputs() const override;
     Outputs enabledOutputs() const override;
 
-    QSize size() const {
-        return screenSize();
-    }
+    QSize size() const;
     QSize screenSize() const override;
 
+    int scale() const;
+
     HwcomposerWindow *createSurface();
 
     hwc_composer_device_1_t *device() const {